Disposable absorbent products, such as disposable diapers and incontinent devices, have become increasingly sophisticated in recent years in an effort to enhance the absorptive and containment characteristics of such products. Products of this nature include an absorbent panel assembly which, in a simple form, typically comprises a batt or panel of comminuted wood pulp, sometimes referred to as wood fluff. In more sophisticated arrangements, superabsorbent polymeric material can be incorporated in the absorbent panel, with layered, or otherwise selectively thickened constructions further promoting efficient use of materials and effective absorption.
One particularly sophisticated and effective absorbent panel construction is disclosed in U.S. Pat. No. 4,500,315, to Pieniak et al. The absorbent material disclosed in this patent comprises a compressed composite laminate of a resilient fibrous web impregnated with in situ polymerized superabsorbent material. One or both sides of the compressed resilient web is provided with a densified layer of comminuted wood pulp, which layer functions to promote wicking and distribution of liquid to all portions of the assembly for efficient use of the superabsorbent material.
While the above-described compressed composite laminate has been found to exhibit superior absorptive and containment characteristics, it will be appreciated that its sophisticated nature results in such a construction being more costly than relatively simple wood pulp absorbent panel arrangements. However, studies have shown that the absorbent panel of a diaper or incontinent product is not usually subjected to uniform wetting, but rather, is subjected to generally localized wetting in a predictable fashion. As such, not all regions of an absorbent panel assembly need exhibit the superior performance characteristics which can be achieved with the above-described compressed composite laminate absorbent material.
Accordingly, the present invention contemplates a method and apparatus for manufacture of an absorbent panel assembly which permits selective placement of a discrete pad of material, such as comprising the above-described compressed composite laminate, in association with a larger absorbent panel which may comprise a less expensive material. In this way, an absorbent panel assembly can be provided with superior absorptive and containment characteristics in a cost-effective manner.